Sum of unique values within a range with blank cells

[loook]

Hi, how can I sum unique values within a range where some cells are
blank?
An example:
A
1 100
2 150
3
4 150
5 50
6
7 100
8 100
9 50
10 SUM = 300 (100 + 150 + 50)

Thanx for any suggestion.

look

 

[Bob Phillips]

=SUMPRODUCT(1/COUNTIF(A1:A10,A1:A10&""),A1:A10)

--
HTH

Bob

(there's no email, no snail mail, but somewhere should be gmail in my addy)

 

[Gary''s Student]

In B1 enter:
=IF(COUNTIF($A$1:A1,A1)=1,A1,"") and copy down
In another cell:
=SUM(B:B)

 

[Teethless mama]

=SUM(INDEX(1/COUNTIF(A1:A9,A1:A9&"")*A1:A9,0))